Although it has long been established that migration and health status are closely linked, identifying the effect of migration on health remains an unresolved challenge for much migration research. This challenge has remained due primarily to data limitations, such as the inability to measure all characteristics that affect both migration and health, or the lack of longitudinal data necessary to distinguish between the effect of migration on health and the selection of individuals of differing health status into migration streams. Furthermore, migration and health research has typically focused on Asia, Europe or North America instead of sub-Saharan Africa (SSA), despite the impact of the HIV/AIDS epidemic on migration patterns, and the high and increasing rates of internal migration in SSA. This proposed study will address these two important gaps in research on the relationship between migration and health by (1) addressing several central methodological challenges that often preclude establishing a causal connection between migration and health, and (2) initiating a regional focus on SSA.